When Serena Williams opened her fourth-round match against Maria Kirilenko by going down 0-40 in her first service game, then was called for a foot-fault on her first serve, there was a palpable stirring among the tennis Twitterati: Were we in for a battle?

The answer came quickly and emphatically, as Williams backed up her second serve with a huge forehand and darted in for a swing volley before peeling off a service winner and two aces to hold a game that would be the only blemish in an almost flawless performance. Williams crushed Kirilenko 6-2, 6-0, to return to the Australian Open quarterfinals for the first time since she won the tournament in 2010.

It would be unkind to suggest that the large insect which surprised Williams on her chair during a late change of ends bothered the American more than her opponent, but it would also probably be true—and not for lack of effort on Kirilenko’s part. This was Williams at her most imperious; Kirilenko, despite her much-improved game, could do very little against it. With Williams hitting 22 winners against just six unforced errors and actually hitting more aces (6) than second serves (5), it’s hard to imagine who could make a dent in her game today—or might be able to in the second week, if she sustains that kind of form.

With Williams’ serve quickly attaining a level where it was plain that Kirilenko wasn’t going to be able to make an impact, the pressure was squarely on the Russian’s serve. It’s a shot that she has worked hard on over the past couple of years, but with Williams smacking returns unerringly back on to her shoelaces, Kirilenko started almost every rally at a disadvantage, having to scoop or slice the ball back. Williams simply teed off on these shots. Kirilenko eked out one service hold before the pressure of Williams’ returns predictably told for a break to 15; she consolidated with the second of four love service games, and it was all over bar the question of how crushing the defeat would be.

Kirilenko did have a couple of nice moments—she dictated successfully with her forehand once or twice, something which would have been unthinkable a few years ago, and managed to make life a little difficult for Williams at the net. But this was the Serena second-week-of-a-Slam show, complete with frustrated reactions to rare misses and furiously dialed-in groundstrokes to back up impeccable serving. My favorite moment came near the end, with Kirilenko serving at 2-6, 0-5, 30-15: The Russian landed one of her best serves of the match, followed up with a great approach that closed down the net. It should have been her point, and she couldn’t really have played a better one, but Williams dipped low to the backhand and produced a passing winner out of nowhere, a short cross-court angle that to all intents and purposes was not there to be found.

Two points later it was all over besides Williams’ post-match interview in which she advised that her quarterfinal opponent, friend and young compatriot Sloane Stephens, was not to be underestimated. Performances like today’s make it doubtful whether Williams, for her part, can be overestimated as a force in this tournament.